/*
   * gd_gd2.c
   *
   * Implements the I/O and support for the GD2 format.
   *
   * Changing the definition of GD2_DBG (below) will cause copious messages
   * to be displayed while it processes requests.
   *
   * Designed, Written & Copyright 1999, Philip Warner.
   *
 */

#include <stdio.h>
#include <errno.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include "gd.h"
#include "gdhelpers.h"

#include <zlib.h>

#define TRUE 1
#define FALSE 0

/* 2.11: not part of the API, as the save routine can figure it out
 *  from im->trueColor, and the load routine doesn't need to tell
 *  the end user the saved format. NOTE: adding 2 is assumed
 *  to result in the correct format value for truecolor!
*/
#define GD2_FMT_TRUECOLOR_RAW 3
#define GD2_FMT_TRUECOLOR_COMPRESSED 4

#define gd2_compressed(fmt) (((fmt) == GD2_FMT_COMPRESSED) || ((fmt) == GD2_FMT_TRUECOLOR_COMPRESSED))
#define gd2_truecolor(fmt) (((fmt) == GD2_FMT_TRUECOLOR_RAW) || ((fmt) == GD2_FMT_TRUECOLOR_COMPRESSED))

/* Use this for commenting out debug-print statements. */
/* Just use the first '#define' to allow all the prints... */
/* #define GD2_DBG(s) (s) */
#define GD2_DBG(s)

typedef struct
{
  int offset;
  int size;
} t_chunk_info;

extern int _gdGetColors(gdIOCtx * in, gdImagePtr im, int gd2xFlag);
extern void _gdPutColors(gdImagePtr im, gdIOCtx * out);

/* */
/* Read the extra info in the gd2 header. */
/* */
static int _gd2GetHeader(gdIOCtxPtr in, int *sx, int *sy, int *cs, int *vers, int *fmt, int *ncx, int *ncy, t_chunk_info ** chunkIdx)
{
  int i;
  int ch;
  char id[5];
  t_chunk_info *cidx;
  int sidx;
  int nc;

  GD2_DBG(php_gd_error("Reading gd2 header info"));

  for (i = 0; i < 4; i++) {
    ch = gdGetC(in);
    if (ch == EOF) {
      goto fail1;
    }
    id[i] = ch;
  }
  id[4] = 0;

  GD2_DBG(php_gd_error("Got file code: %s", id));

  /* Equiv. of 'magick'.  */
  if (strcmp(id, GD2_ID) != 0) {
    GD2_DBG(php_gd_error("Not a valid gd2 file"));
    goto fail1;
  }

  /* Version */
  if (gdGetWord(vers, in) != 1) {
    goto fail1;
  }
  GD2_DBG(php_gd_error("Version: %d", *vers));

  if ((*vers != 1) && (*vers != 2)) {
    GD2_DBG(php_gd_error("Bad version: %d", *vers));
    goto fail1;
  }

  /* Image Size */
  if (!gdGetWord(sx, in)) {
    GD2_DBG(php_gd_error("Could not get x-size"));
    goto fail1;
  }
  if (!gdGetWord(sy, in)) {
    GD2_DBG(php_gd_error("Could not get y-size"));
    goto fail1;
  }
  GD2_DBG(php_gd_error("Image is %dx%d", *sx, *sy));

  /* Chunk Size (pixels, not bytes!) */
  if (gdGetWord(cs, in) != 1) {
    goto fail1;
  }
  GD2_DBG(php_gd_error("ChunkSize: %d", *cs));

  if ((*cs < GD2_CHUNKSIZE_MIN) || (*cs > GD2_CHUNKSIZE_MAX)) {
    GD2_DBG(php_gd_error("Bad chunk size: %d", *cs));
    goto fail1;
  }

  /* Data Format */
  if (gdGetWord(fmt, in) != 1) {
    goto fail1;
  }
  GD2_DBG(php_gd_error("Format: %d", *fmt));

  if ((*fmt != GD2_FMT_RAW) && (*fmt != GD2_FMT_COMPRESSED) && (*fmt != GD2_FMT_TRUECOLOR_RAW) && (*fmt != GD2_FMT_TRUECOLOR_COMPRESSED)) {
    GD2_DBG(php_gd_error("Bad data format: %d", *fmt));
    goto fail1;
  }

  /* # of chunks wide */
  if (gdGetWord(ncx, in) != 1) {
    goto fail1;
  }
  GD2_DBG(php_gd_error("%d Chunks Wide", *ncx));

  /* # of chunks high */
  if (gdGetWord(ncy, in) != 1) {
    goto fail1;
  }
  GD2_DBG(php_gd_error("%d Chunks vertically", *ncy));

  if (gd2_compressed(*fmt)) {
    nc = (*ncx) * (*ncy);
    GD2_DBG(php_gd_error("Reading %d chunk index entries", nc));
    if (overflow2(sizeof(t_chunk_info), nc)) {
      goto fail1;
    }
    sidx = sizeof(t_chunk_info) * nc;
    if (sidx <= 0) {
      goto fail1;
    }
    cidx = (t_chunk_info*) gdCalloc(sidx, 1);
    if (cidx == NULL) {
      goto fail1;
    }
    for (i = 0; i < nc; i++) {
      if (gdGetInt(&cidx[i].offset, in) != 1) {
        goto fail1;
      }
      if (gdGetInt(&cidx[i].size, in) != 1) {
        goto fail1;
      }
      if (cidx[i].offset < 0 || cidx[i].size < 0) {
        goto fail1;
      }
    }
    *chunkIdx = cidx;
  }

  GD2_DBG(php_gd_error("gd2 header complete"));

  return 1;

fail1:
  return 0;
}

static gdImagePtr _gd2CreateFromFile (gdIOCtxPtr in, int *sx, int *sy, int *cs, int *vers, int *fmt, int *ncx, int *ncy, t_chunk_info ** cidx)
{
  gdImagePtr im;

  if (_gd2GetHeader (in, sx, sy, cs, vers, fmt, ncx, ncy, cidx) != 1) {
    GD2_DBG(php_gd_error("Bad GD2 header"));
    goto fail1;
  }

  if (gd2_truecolor(*fmt)) {
    im = gdImageCreateTrueColor(*sx, *sy);
  } else {
    im = gdImageCreate(*sx, *sy);
  }
  if (im == NULL) {
    GD2_DBG(php_gd_error("Could not create gdImage"));
    goto fail1;
  }

  if (!_gdGetColors(in, im, (*vers) == 2)) {
    GD2_DBG(php_gd_error("Could not read color palette"));
    goto fail2;
  }
  GD2_DBG(php_gd_error("Image palette completed: %d colours", im->colorsTotal));

  return im;

fail2:
  gdImageDestroy(im);
  return 0;

fail1:
  return 0;
}

static int _gd2ReadChunk (int offset, char *compBuf, int compSize, char *chunkBuf, uLongf * chunkLen, gdIOCtx * in)
{
  int zerr;

  if (gdTell(in) != offset) {
    GD2_DBG(php_gd_error("Positioning in file to %d", offset));
    gdSeek(in, offset);
  } else {
    GD2_DBG(php_gd_error("Already Positioned in file to %d", offset));
  }

  /* Read and uncompress an entire chunk. */
  GD2_DBG(php_gd_error("Reading file"));
  if (gdGetBuf(compBuf, compSize, in) != compSize) {
    return FALSE;
  }
  GD2_DBG(php_gd_error("Got %d bytes. Uncompressing into buffer of %d bytes", compSize, (int)*chunkLen));
  zerr = uncompress((unsigned char *) chunkBuf, chunkLen, (unsigned char *) compBuf, compSize);
  if (zerr != Z_OK) {
    GD2_DBG(php_gd_error("Error %d from uncompress", zerr));
    return FALSE;
  }
  GD2_DBG(php_gd_error("Got chunk"));

  return TRUE;
}

gdImagePtr gdImageCreateFromGd2 (FILE * inFile)
{
  gdIOCtx *in = gdNewFileCtx(inFile);
  gdImagePtr im;

  im = gdImageCreateFromGd2Ctx(in);

  in->gd_free(in);

  return im;
}

gdImagePtr gdImageCreateFromGd2Ptr (int size, void *data)
{
  gdImagePtr im;
  gdIOCtx *in = gdNewDynamicCtxEx(size, data, 0);
  im = gdImageCreateFromGd2Ctx(in);
  in->gd_free(in);

  return im;
}

gdImagePtr gdImageCreateFromGd2Ctx (gdIOCtxPtr in)
{
  int sx, sy;
  int i;
  int ncx, ncy, nc, cs, cx, cy;
  int x, y, ylo, yhi, xlo, xhi;
  int vers, fmt;
  t_chunk_info *chunkIdx = NULL;  /* So we can gdFree it with impunity. */
  unsigned char *chunkBuf = NULL; /* So we can gdFree it with impunity. */
  int chunkNum = 0;
  int chunkMax = 0;
  uLongf chunkLen;
  int chunkPos = 0;
  int compMax = 0;
  int bytesPerPixel;
  char *compBuf = NULL;   /* So we can gdFree it with impunity. */

  gdImagePtr im;

  /* Get the header */
  if (!(im = _gd2CreateFromFile(in, &sx, &sy, &cs, &vers, &fmt, &ncx, &ncy, &chunkIdx))) {
     return 0;
  }

  bytesPerPixel = im->trueColor ? 4 : 1;
  nc = ncx * ncy;

  if (gd2_compressed(fmt)) {
    /* Find the maximum compressed chunk size. */
    compMax = 0;
    for (i = 0; (i < nc); i++) {
      if (chunkIdx[i].size > compMax) {
        compMax = chunkIdx[i].size;
      }
    }
    compMax++;

    /* Allocate buffers */
    chunkMax = cs * bytesPerPixel * cs;
    if (chunkMax <= 0) {
      return 0;
    }
    chunkBuf = (unsigned char*) gdCalloc(chunkMax, 1);
    compBuf = (char*) gdCalloc(compMax, 1);

    GD2_DBG(php_gd_error("Largest compressed chunk is %d bytes", compMax));
  }

  /* Read the data... */
  for (cy = 0; (cy < ncy); cy++) {
    for (cx = 0; (cx < ncx); cx++) {
      ylo = cy * cs;
      yhi = ylo + cs;
      if (yhi > im->sy) {
        yhi = im->sy;
      }

      GD2_DBG(php_gd_error("Processing Chunk %d (%d, %d), y from %d to %d", chunkNum, cx, cy, ylo, yhi));

      if (gd2_compressed(fmt)) {
        chunkLen = chunkMax;

        if (!_gd2ReadChunk(chunkIdx[chunkNum].offset, compBuf, chunkIdx[chunkNum].size, (char *) chunkBuf, &chunkLen, in)) {
          GD2_DBG(php_gd_error("Error reading comproessed chunk"));
          goto fail2;
        }

        chunkPos = 0;
      }

      for (y = ylo; (y < yhi); y++) {
        xlo = cx * cs;
        xhi = xlo + cs;
        if (xhi > im->sx) {
          xhi = im->sx;
        }

        if (!gd2_compressed(fmt)) {
          for (x = xlo; x < xhi; x++) {
            if (im->trueColor) {
              if (!gdGetInt(&im->tpixels[y][x], in)) {
                im->tpixels[y][x] = 0;
              }
            } else {
              int ch;
              if (!gdGetByte(&ch, in)) {
                ch = 0;
              }
              im->pixels[y][x] = ch;
            }
          }
        } else {
          for (x = xlo; x < xhi; x++) {
            if (im->trueColor) {
              /* 2.0.1: work around a gcc bug by being verbose. TBB */
              int a = chunkBuf[chunkPos++] << 24;
              int r = chunkBuf[chunkPos++] << 16;
              int g = chunkBuf[chunkPos++] << 8;
              int b = chunkBuf[chunkPos++];
              im->tpixels[y][x] = a + r + g + b;
            } else {
              im->pixels[y][x] = chunkBuf[chunkPos++];
            }
          }
        }
      }
      chunkNum++;
    }
  }

  GD2_DBG(php_gd_error("Freeing memory"));

  if (chunkBuf) {
    gdFree(chunkBuf);
  }
  if (compBuf) {
    gdFree(compBuf);
  }
  if (chunkIdx) {
    gdFree(chunkIdx);
  }

  GD2_DBG(php_gd_error("Done"));

  return im;

fail2:
  gdImageDestroy(im);
  if (chunkBuf) {
    gdFree(chunkBuf);
  }
  if (compBuf) {
    gdFree(compBuf);
  }
  if (chunkIdx) {
    gdFree(chunkIdx);
  }

  return 0;
}

gdImagePtr gdImageCreateFromGd2PartPtr (int size, void *data, int srcx, int srcy, int w, int h)
{
  gdImagePtr im;
  gdIOCtx *in = gdNewDynamicCtxEx(size, data, 0);
  im = gdImageCreateFromGd2PartCtx(in, srcx, srcy, w, h);
  in->gd_free(in);

  return im;
}

gdImagePtr gdImageCreateFromGd2Part (FILE * inFile, int srcx, int srcy, int w, int h)
{
  gdImagePtr im;
  gdIOCtx *in = gdNewFileCtx(inFile);

  im = gdImageCreateFromGd2PartCtx(in, srcx, srcy, w, h);

  in->gd_free(in);

  return im;
}

gdImagePtr gdImageCreateFromGd2PartCtx (gdIOCtx * in, int srcx, int srcy, int w, int h)
{
  int scx, scy, ecx, ecy, fsx, fsy;
  int nc, ncx, ncy, cs, cx, cy;
  int x, y, ylo, yhi, xlo, xhi;
  int dstart, dpos;
  int i;
  /* 2.0.12: unsigned is correct; fixes problems with color munging. Thanks to Steven Brown. */
  unsigned int ch;
  int vers, fmt;
  t_chunk_info *chunkIdx = NULL;
  unsigned char *chunkBuf = NULL;
  int chunkNum;
  int chunkMax = 0;
  uLongf chunkLen;
  int chunkPos = 0;
  int compMax;
  char *compBuf = NULL;

  gdImagePtr im;

  if (w<1 || h <1) {
    return 0;
  }

  /* The next few lines are basically copied from gd2CreateFromFile
   * we change the file size, so don't want to use the code directly.
   * but we do need to know the file size.
   */
  if (_gd2GetHeader(in, &fsx, &fsy, &cs, &vers, &fmt, &ncx, &ncy, &chunkIdx) != 1) {
    goto fail1;
  }

  GD2_DBG(php_gd_error("File size is %dx%d", fsx, fsy));

  /* This is the difference - make a file based on size of chunks. */
  if (gd2_truecolor(fmt)) {
    im = gdImageCreateTrueColor(w, h);
  } else {
    im = gdImageCreate(w, h);
  }
  if (im == NULL) {
    goto fail1;
  }

  if (!_gdGetColors(in, im, vers == 2)) {
    goto fail2;
  }
  GD2_DBG(php_gd_error("Image palette completed: %d colours", im->colorsTotal));

  /* Process the header info */
  nc = ncx * ncy;

  if (gd2_compressed(fmt)) {
    /* Find the maximum compressed chunk size. */
    compMax = 0;
    for (i = 0; (i < nc); i++) {
      if (chunkIdx[i].size > compMax) {
        compMax = chunkIdx[i].size;
      }
    }
    compMax++;

    if (im->trueColor) {
      chunkMax = cs * cs * 4;
    } else {
      chunkMax = cs * cs;
    }
    if (chunkMax <= 0) {
      goto fail2;
    }

    chunkBuf = (unsigned char*) gdCalloc(chunkMax, 1);
    compBuf = (char*) gdCalloc(compMax, 1);
  }

  /* Work out start/end chunks */
  scx = srcx / cs;
  scy = srcy / cs;
  if (scx < 0) {
    scx = 0;
  }
  if (scy < 0) {
    scy = 0;
  }

  ecx = (srcx + w) / cs;
  ecy = (srcy + h) / cs;
  if (ecx >= ncx) {
    ecx = ncx - 1;
  }
  if (ecy >= ncy) {
    ecy = ncy - 1;
  }

  /* Remember file position of image data. */
  dstart = gdTell(in);
  GD2_DBG(php_gd_error("Data starts at %d", dstart));

  /* Loop through the chunks. */
  for (cy = scy; (cy <= ecy); cy++) {
    ylo = cy * cs;
    yhi = ylo + cs;
    if (yhi > fsy) {
      yhi = fsy;
    }

    for (cx = scx; cx <= ecx; cx++) {

      xlo = cx * cs;
      xhi = xlo + cs;
      if (xhi > fsx) {
        xhi = fsx;
      }

      GD2_DBG(php_gd_error("Processing Chunk (%d, %d), from %d to %d", cx, cy, ylo, yhi));

      if (!gd2_compressed(fmt)) {
        GD2_DBG(php_gd_error("Using raw format data"));
        if (im->trueColor) {
          dpos = (cy * (cs * fsx) * 4 + cx * cs * (yhi - ylo) * 4) + dstart;
        } else {
          dpos = cy * (cs * fsx) + cx * cs * (yhi - ylo) + dstart;
        }

        /* gd 2.0.11: gdSeek returns TRUE on success, not 0. Longstanding bug. 01/16/03 */
        if (!gdSeek(in, dpos)) {
          php_gd_error_ex(E_WARNING, "Error from seek: %d", errno);
          goto fail2;
        }
        GD2_DBG(php_gd_error("Reading (%d, %d) from position %d", cx, cy, dpos - dstart));
      } else {
        chunkNum = cx + cy * ncx;

        chunkLen = chunkMax;
        if (!_gd2ReadChunk (chunkIdx[chunkNum].offset, compBuf, chunkIdx[chunkNum].size, (char *)chunkBuf, &chunkLen, in)) {
          php_gd_error("Error reading comproessed chunk");
          goto fail2;
        }
        chunkPos = 0;
        GD2_DBG(php_gd_error("Reading (%d, %d) from chunk %d", cx, cy, chunkNum));
      }

      GD2_DBG(php_gd_error("   into (%d, %d) - (%d, %d)", xlo, ylo, xhi, yhi));

      for (y = ylo; (y < yhi); y++) {
        for (x = xlo; x < xhi; x++) {
          if (!gd2_compressed(fmt)) {
            if (im->trueColor) {
              if (!gdGetInt((int *)&ch, in)) {
                ch = 0;
              }
            } else {
              ch = gdGetC(in);
              if ((int)ch == EOF) {
                ch = 0;
              }
            }
          } else {
            if (im->trueColor) {
              ch = chunkBuf[chunkPos++];
              ch = (ch << 8) + chunkBuf[chunkPos++];
              ch = (ch << 8) + chunkBuf[chunkPos++];
              ch = (ch << 8) + chunkBuf[chunkPos++];
            } else {
              ch = chunkBuf[chunkPos++];
            }
          }

          /* Only use a point that is in the image. */
          if ((x >= srcx) && (x < (srcx + w)) && (x < fsx) && (x >= 0) && (y >= srcy) && (y < (srcy + h)) && (y < fsy) && (y >= 0)) {
            if (im->trueColor) {
              im->tpixels[y - srcy][x - srcx] = ch;
            } else {
              im->pixels[y - srcy][x - srcx] = ch;
            }
          }
        }
      }
    }
  }

  if (chunkBuf) {
    gdFree(chunkBuf);
  }
  if (compBuf) {
    gdFree(compBuf);
  }
  if (chunkIdx) {
    gdFree(chunkIdx);
  }

  return im;

fail2:
  gdImageDestroy(im);
fail1:
  if (chunkBuf) {
    gdFree(chunkBuf);
  }
  if (compBuf) {
    gdFree(compBuf);
  }
  if (chunkIdx) {
    gdFree(chunkIdx);
  }

  return 0;
}

static void _gd2PutHeader (gdImagePtr im, gdIOCtx * out, int cs, int fmt, int cx, int cy)
{
  int i;

  /* Send the gd2 id, to verify file format. */
  for (i = 0; i < 4; i++) {
    gdPutC((unsigned char) (GD2_ID[i]), out);
  }

  /* We put the version info first, so future versions can easily change header info. */

  gdPutWord(GD2_VERS, out);
  gdPutWord(im->sx, out);
  gdPutWord(im->sy, out);
  gdPutWord(cs, out);
  gdPutWord(fmt, out);
  gdPutWord(cx, out);
  gdPutWord(cy, out);
}

static void _gdImageGd2 (gdImagePtr im, gdIOCtx * out, int cs, int fmt)
{
  int ncx, ncy, cx, cy;
  int x, y, ylo, yhi, xlo, xhi;
  int chunkLen;
  int chunkNum = 0;
  char *chunkData = NULL; /* So we can gdFree it with impunity. */
  char *compData = NULL;  /* So we can gdFree it with impunity. */
  uLongf compLen;
  int idxPos = 0;
  int idxSize;
  t_chunk_info *chunkIdx = NULL; /* So we can gdFree it with impunity. */
  int posSave;
  int bytesPerPixel = im->trueColor ? 4 : 1;
  int compMax = 0;

  /* Force fmt to a valid value since we don't return anything. */
  if ((fmt != GD2_FMT_RAW) && (fmt != GD2_FMT_COMPRESSED)) {
    fmt = GD2_FMT_COMPRESSED;
  }
  if (im->trueColor) {
    fmt += 2;
                assert(fmt == GD2_FMT_TRUECOLOR_RAW ||
                       fmt == GD2_FMT_TRUECOLOR_COMPRESSED);
  }
  /* Make sure chunk size is valid. These are arbitrary values; 64 because it seems
   * a little silly to expect performance improvements on a 64x64 bit scale, and
   * 4096 because we buffer one chunk, and a 16MB buffer seems a little large - it may be
   * OK for one user, but for another to read it, they require the buffer.
   */
  if (cs == 0) {
    cs = GD2_CHUNKSIZE;
  } else if (cs < GD2_CHUNKSIZE_MIN) {
    cs = GD2_CHUNKSIZE_MIN;
  } else if (cs > GD2_CHUNKSIZE_MAX) {
    cs = GD2_CHUNKSIZE_MAX;
  }

  /* Work out number of chunks. */
  ncx = im->sx / cs + 1;
  ncy = im->sy / cs + 1;

  /* Write the standard header. */
  _gd2PutHeader (im, out, cs, fmt, ncx, ncy);

  if (gd2_compressed(fmt)) {
    /* Work out size of buffer for compressed data, If CHUNKSIZE is large,
     * then these will be large!
     */

    /* The zlib notes say output buffer size should be (input size) * 1.01 * 12
     * - we'll use 1.02 to be paranoid.
     */
    compMax = (int)(cs * bytesPerPixel * cs * 1.02f) + 12;

    /* Allocate the buffers.  */
    chunkData = (char*) safe_emalloc(cs * bytesPerPixel, cs, 0);
    memset(chunkData, 0, cs * bytesPerPixel * cs);
    if (compMax <= 0) {
      goto fail;
    }
    compData = (char*) gdCalloc(compMax, 1);

    /* Save the file position of chunk index, and allocate enough space for
     * each chunk_info block .
     */
    idxPos = gdTell(out);
    idxSize = ncx * ncy * sizeof(t_chunk_info);
    GD2_DBG(php_gd_error("Index size is %d", idxSize));
    gdSeek(out, idxPos + idxSize);

    chunkIdx = (t_chunk_info*) safe_emalloc(idxSize, sizeof(t_chunk_info), 0);
    memset(chunkIdx, 0, idxSize * sizeof(t_chunk_info));
  }

  _gdPutColors (im, out);

  GD2_DBG(php_gd_error("Size: %dx%d", im->sx, im->sy));
  GD2_DBG(php_gd_error("Chunks: %dx%d", ncx, ncy));

  for (cy = 0; (cy < ncy); cy++) {
    for (cx = 0; (cx < ncx); cx++) {
      ylo = cy * cs;
      yhi = ylo + cs;
      if (yhi > im->sy) {
        yhi = im->sy;
      }

      GD2_DBG(php_gd_error("Processing Chunk (%dx%d), y from %d to %d", cx, cy, ylo, yhi));
      chunkLen = 0;
      for (y = ylo; (y < yhi); y++) {
        GD2_DBG(php_gd_error("y=%d: ",y));
        xlo = cx * cs;
        xhi = xlo + cs;
        if (xhi > im->sx) {
          xhi = im->sx;
        }

        if (gd2_compressed(fmt)) {
          for (x = xlo; x < xhi; x++) {
            GD2_DBG(php_gd_error("%d...",x));
            if (im->trueColor) {
              int p = im->tpixels[y][x];
              chunkData[chunkLen++] = gdTrueColorGetAlpha(p);
              chunkData[chunkLen++] = gdTrueColorGetRed(p);
              chunkData[chunkLen++] = gdTrueColorGetGreen(p);
              chunkData[chunkLen++] = gdTrueColorGetBlue(p);
            } else {
              chunkData[chunkLen++] = im->pixels[y][x];
            }
          }
        } else {
          for (x = xlo; x < xhi; x++) {
            GD2_DBG(php_gd_error("%d, ",x));

            if (im->trueColor) {
              gdPutInt(im->tpixels[y][x], out);
            } else {
              gdPutC((unsigned char) im->pixels[y][x], out);
            }
          }
        }
        GD2_DBG(php_gd_error("y=%d done.",y));
      }

      if (gd2_compressed(fmt)) {
        compLen = compMax;
        if (compress((unsigned char *) &compData[0], &compLen, (unsigned char *) &chunkData[0], chunkLen) != Z_OK) {
          php_gd_error("Error from compressing");
        } else {
          chunkIdx[chunkNum].offset = gdTell(out);
          chunkIdx[chunkNum++].size = compLen;
          GD2_DBG(php_gd_error("Chunk %d size %d offset %d", chunkNum, chunkIdx[chunkNum - 1].size, chunkIdx[chunkNum - 1].offset));

          if (gdPutBuf (compData, compLen, out) <= 0) {
            /* Any alternate suggestions for handling this? */
            php_gd_error_ex(E_WARNING, "Error %d on write", errno);
          }
        }
      }
    }
      }

  if (gd2_compressed(fmt)) {
    /* Save the position, write the index, restore position (paranoia). */
    GD2_DBG(php_gd_error("Seeking %d to write index", idxPos));
    posSave = gdTell(out);
    gdSeek(out, idxPos);
    GD2_DBG(php_gd_error("Writing index"));
    for (x = 0; x < chunkNum; x++) {
      GD2_DBG(php_gd_error("Chunk %d size %d offset %d", x, chunkIdx[x].size, chunkIdx[x].offset));
      gdPutInt(chunkIdx[x].offset, out);
      gdPutInt(chunkIdx[x].size, out);
    }
    gdSeek(out, posSave);
  }
fail:
  GD2_DBG(php_gd_error("Freeing memory"));
  if (chunkData) {
    gdFree(chunkData);
  }
  if (compData) {
    gdFree(compData);
  }
  if (chunkIdx) {
    gdFree(chunkIdx);
  }
  GD2_DBG(php_gd_error("Done"));
}

void gdImageGd2 (gdImagePtr im, FILE * outFile, int cs, int fmt)
{
  gdIOCtx *out = gdNewFileCtx(outFile);

  _gdImageGd2(im, out, cs, fmt);

  out->gd_free(out);
}

void *gdImageGd2Ptr (gdImagePtr im, int cs, int fmt, int *size)
{
  void *rv;
  gdIOCtx *out = gdNewDynamicCtx(2048, NULL);

  _gdImageGd2(im, out, cs, fmt);
  rv = gdDPExtractData(out, size);
  out->gd_free(out);

  return rv;
}
